Mechanics

P1077

2004 Honda CRV • 4 cylinder 2WD Automatic • 180,000 miles

How to repair code p1077
Avatar
Nsanchun
August 12, 2011.



DTC P1077: IMRC SYSTEM MALFUNCTION (LOW RPM)

Special Tools Required

Vacuum pump/gauge, 0-3 in. Hg A973X-041-XXXXX

1. Reset the ECM/PCM.

2. Start the engine, and hold it at 3,000 RPM with no load (in Park or neutral) until the radiator fan comes on. Is DTC P1077 indicated?

YES - Go to step 3.

NO - Intermittent failure, system is OK at this time. Check for poor
connections or loose terminals at the intake manifold runner control
(IMRC) solenoid valve and at the ECM/PCM.

3. Disconnect the vacuum hose (A) from the intake manifold runner control (IMRC) actuator (B), and connect a vacuum pump to the hose.

Is there vacuum with the engine at idle?

YES - Go to step 11.

NO - Go to step 4.

4. Check the vacuum hose between the IMRC actuator and IMRC solenoid valve.
Is the vacuum hose OK?

YES - Go to step 5.

NO - Repair the blockage or vacuum leak between the IMRC actuator and
IMRC solenoid valve.

5. Disconnect the lower vacuum hose (A) from the IMRC solenoid valve (B), and connect a vacuum pump to the hose.

Is there vacuum?

YES - Go to step 6.

NO - Repair the blockage or vacuum leak between the intake manifold and IMRC solenoid valve.

6. Reconnect the lower vacuum hose to the IMRC solenoid valve, and connect a vacuum pump to the vacuum hose (A).

7. Disconnect the IMRC solenoid valve 2P connector.
Is there vacuum?

YES - Go to step 8.

NO - Replace the IMRC solenoid valve.

8. Turn the ignition switch OFF.

9. Disconnect ECM/PCM connector B (24P).

10. Check for continuity between IMRC solenoid valve 2P connector terminal No. 2 and body ground.

Is there continuity?

YES - Repair short in the wire between the ECM/PCM (B22) and the
IMRC solenoid valve.

NO - Update the ECM/PCM if it does not have the latest software, or
substitute a known-good ECM/PCM, then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the
original ECM/PCM.

11. Turn the ignition switch OFF.

12. Connect a vacuum pump to the IMRC actuator (A), then apply vacuum.

Does the IMRC actuator hold vacuum?

YES - Go to step 13.

NO - Replace the IMRC valve assembly.

13. Disconnect the IMRC valve position sensor 3P connector.

14. At the sensor side, measure resistance between IMRC valve position sensor 3P connector terminals No. 2 and No. 3.

Is there about 9.5 kohm at room temperature?

YES - Update the ECM/PCM if it does not have the latest software, or
substitute a known-good ECM/PCM, then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the
original ECM/PCM.

NO - Replace the IMRC valve assembly.


KHLow2008
Aug 12, 2011.